GRRR!! Nothing like having your plans ruined

I wonder if he DID have the time when he first scheduled the time off but then ended up using hours after that that then put him below the number needed?

If he didn't have the hours on the books that should have been addressed weeks before he left for vacation and arrangements made. For those that have the use it or loose it you usually know for a month or so before hand and just use it earlier. This is common and if this is your busy time then you use the time before the busy season hits. Employees should be able to check the number of hours/days they have on the books and how many can be carried over. This is so common and I know at my husbands job they suggest when to take the time off - you don't have to use it at that time but it is highly recommended and luckily it usually works out fine for us so he takes it then. It sounds like a lot of policies need to be put into place to prevent hard feelings and people taking advantage or just leaving you understaffed in the future. The idea that a person can approve it when it is a time that you will be understaffed makes no sense. Now those that don't come in when scheduled on a regular basis - HR need to get involved that is unacceptable anywhere. Obviously things come up and exceptions need to be made but if it is the same person all the time unless it really is an emergency HR needs to step in and there needs to be a process to remove them. It also depends on what kind of job it is. I know at hubby's job there are several that are dealing with sick spouses and they are working around it as much as possible but it all depends on what kind of job you have. Others have stepped up but they have all been there for more than a decade so not a high turnover type of place.

Good luck to your husband having to deal with being put in a situation to try and fix it.